Ultimate Rebide is able to absorb quite literally any kind of energy, be it thermal, kinetic, potential, etcetera. Absorbing different energy types can have varied effects on the target; for example, absorbing a target's kinetic energy will stop them in their tracks, whereas absorbing their potential energy will leave them unable to move until they produce more.
Ultimate Rebide resembles a larger, bulkier version of its unevolved form. It has four barbels, which it uses to craft the energy spheres and beams it fires, and its arms split at the elbow.
Like its unevolved form, it has no mouth, but has gained an eye in the center of its abdomen that is also capable of shooting energy beams, albeit without nearly as much dexterity as the barbels.
Ultimate Rebide is even slower and heavier than his original form, making any attempt at walking look like a somewhat humorous waddle.